Alternating-electric-current generating and distributing system.



No. 695,937. Patented Mar. 25, I902. B. G. LAMME.

ALTERNATING ELECTRIC CURRENT GENERATING AND DISTRIBUTING SYSTEM.

(Applicltion filed July 31,1896.)

(No NlodeI.)

UNITE STATES PATENT OFFICE.

BENJAMIN G. LAMME, OF PITTSBURG, PENNSYLVANIA, ASSIGNOR TO WVESTINGHOUSEELECTRIC AND MANUFACTURING COMPANY, OF

PITTSBURG, PENNSYLVANIA.

ALTERNATlNG-ELECTRIC-CURRENT GENERATING AND DISIRIBUTlNG SYSTEM,

SIPEOlFllCATION forming part of Letters Patent No. 695,937, dated. March25, 1902,

Application filed July 31, 1896 To all whom it may concern:

Be it known that I, BENJAMIN G. LAMME, a citizen of the United States,residing in Pittsburg, in the county of Allegheny and State ofPennsylvania, have invented a new and usefullmprovement inAlternating-Electrio-Current Generating and Distributing Systems, (CaseNo. 709,) of which the following is a specification.

Myinventiou relates to the generation and distribution of electricalenergy; and it has for its object to utilize a machine having asecondary member provided with a closedcircuit winding as the mainsource of current for the work-circuit and to utilize one or moresynchronous motors as the exciting means for such generator.

It has been found in practice that if the primary member of aninduction-machine be supplied with alternating impulses from anysuitable source and the rotatable member of such machine be mechanicallydriven by any suitable means at a speed above that of synchronism withthe said source of alternating impulsesthat is to say, at a speedexceeding the frequency of alternations divided by the number ofpoles-it will build up its own field by induction and supply current tothe ex ternal circuit, it being understood that a complete period orcycle comprises two alternations.

If the source of exciting-current is a device or machine having a fixedrate of alternations-such, for example, as an alternatingcurrentgenerator having field-magnets of fixed polaritythe rate of alternationsof the system will be that of said source and will be independent of theinduction-generator. i have found, moreover, that the induction-machinemay be run as a generator to supply the translating devices with workingcurrent without the employment of another machine which is runcontinuously or regularly as a generator.

If a so-called synchronous motor2 6., one having field-magnets of fixedpolarity be included in the circuit, it may be utilized to afford theinitial exciting-current for the induction-generator, provided suchgenerator is first speedcd up and the motor is run Serial No. 601,183.(No model.)

as a generator a sufiicient length of time to effect the building up ofthe field of the induction-machine. The power applied to the shaft ofthe mote: may then be discontinued. It will then run as a motor and itscounter electromotive force will afford the exciting impulses necessaryfor the induction-generator. During the time that the synchronous motoris run as a generator it will fix the alternations of the system; butwhen it is run as a motor the alternations of the systeniwill dependupon the speed of rotation, the number of poles, and the slip of theinductionmachine.

Reference being had to the accompanying drawing, which illustratesdiagrammatically my invention, 1 is an alternating-current motor havingfield-magnets of fixed polarity preferably energized by means of aseparate exciter 2.

3 is an ind notion machine the rotatable member a of which ismechanically driven by any suitable source of power, a counter-shaft andpulley 5 and a belt 6 being shown in the drawing as power-transmittingmeans. As the member at is provided with the inducingcircuit, it willfor convenience be hereinafter termed the field-magnet.

In the form of machine shown one or more closed-circuit windings 7 areapplied to the stationary member or armature, and the primary winding 8on the rotatable member or field-magnet is connected to collecting-rings9, on which bear brushes 10. The leads 11 from the brushes 10 areconnected across the mains 12, leading from the machine 1.

13 represents variable resistances, which may be included in whole or inpart in the secondary or armature circuit of the machine 3, if foundnecessary or-desirable, during the building up of the field of suchmachine.

It is not deem-ed necessary to illustrate the structural details of theinduction-machine employed, since this class of machines is well knownin the art, and the invention is not limited to any specialconstruction.

lei and 15 represent translating devices supplied with current from themains 12.

It will be understood from the foregoing description that alternatingimpulses derived from the motor 1 will be imparted to the primary orfield-magnet winding of the generator and will constitute the necessaryenergy for establishing the magnetic field of such generator. It willalso be understood that m yinvention is particularly useful inconnection with circuits that are utilized either partially or whollyfor operating. synchronous machines, and it is of course immaterial, sofar as my invention is concerned, whether such machines transform theelectrical energy received by them into mechanical energy or intoelectrical energy of a different kind, provided they are driven by theenergy received.

While I have shown an induction-generator of that type in which theprimary member or field-magnet rotates, it will be understood that thereverse arrangementis includedwithin the scope ofmy invention.

It will also be understood that my invention is adapted to and includesthe generation of polyphase currents as well as the single- .phasecurrents described.

I claim as my invention- 1. The combination with an electric circuitcontaining a motor or motors having fieldmagnets of fixed polarity, of amachine having a secondary winding closed upon itself and having aprimary winding connected to said circuit and receiving itsexciting-current solely from said motor or motors and driven as agenerator to supply current to said circuit.

2. In an alternating-current generating and distributing system, thecombination with a work-circuit containing motors having fieldmagnets offixed polarity, of a generator for said circuit having a primarywindingreceiving exciting-current solely from said motors and supplying workingcurrent to said circuit and having a secondary winding closed uponitself and excited by induction from said primary winding.

In testimony whereof I have hereunto subscribed my name this 29th day ofJuly, A. D. 1896.

BENJ. G. LAMME.

Witnesses:

HUBERT O. TENER,

WESLEY G. CARR.

